Study of stellite-6 deposition by cold gas spraying

Abstract

Cold gas spraying (CGS) has been used to generate coatings using ductile materials which are easily deformed with the impact generated by the high kinetic energy of the process. The deposition of less ductile materials is being a challenge.The present work is intended to study the deposition behavior of a stellite alloy whose high mechanical strength hinders its plastic deformation. For this purpose, we evaluated the influence of spraying parameters such as distance and, gas temperature and pressure on the properties of cold sprayed stellite 6 coatings deposited onto steel substrates. Various sets of parameters were tested in order to optimize the porosity, thickness, and deposition efficiency of the stellite coatings and thereby achieve coatings with demonstrated hardness and corrosion and wear resistance.The results show that the two most important parameters for CGS are distance and gas pressure. These two parameters are correlated to coating quality in the way that higher distance and pressure produce lower deposition efficiencies (DEs) and increased porosity contents. Temperature, the third parameter in importance, is positively correlated to quality, thus an improved coating (i.e. dense and with higher DE) can be achieved by increasing this factor.